ADA4961 evaluation board not working

I have the ADA4961 evaluation board EV-ADA4961SDP1Z and it is not working even though the SPI interface software seems to work all right.

There is an instruction to load the eeprom file ADA4961_eval_board.sdpeeprom, but it was not included in the software driver archive and I can't find it on the Analog Devices website.  Is this still needed?


The signal going in to the evaluation board is being attenuated when, according to the SPI settings, it should be amplified by 15 dB.


Please help with some troubleshooting ideas if you can.


Thanks,

Mike


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  • 0
    •  Analog Employees 
    on Feb 5, 2015 7:07 AM over 6 years ago

    Hi, Mike,

        There are a couple of baluns and also PI-attenuators connected to the input and output of the ADA4961 on the evaluation board (cf. schematic on p. 23 of the datasheet).  The input attenuator has 3 dB loss, and the output one has 10 dB loss, and the two baluns together add another 3 dB of loss, totaling up to 16 dB.  So a signal passing through the EVB would see a  power gain (from 50 ohm source to 50 ohm load) of 18 - 16 = 2 dB, when the gain of the device is set to its max.

        Is this what you observed?  If not, please provide more details about device setting, supply current, and signal voltage levels at the input and output pins of the device, so we can make further investigation.

        Thanks!

    Benjamin

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  • 0
    •  Analog Employees 
    on Feb 5, 2015 7:07 AM over 6 years ago

    Hi, Mike,

        There are a couple of baluns and also PI-attenuators connected to the input and output of the ADA4961 on the evaluation board (cf. schematic on p. 23 of the datasheet).  The input attenuator has 3 dB loss, and the output one has 10 dB loss, and the two baluns together add another 3 dB of loss, totaling up to 16 dB.  So a signal passing through the EVB would see a  power gain (from 50 ohm source to 50 ohm load) of 18 - 16 = 2 dB, when the gain of the device is set to its max.

        Is this what you observed?  If not, please provide more details about device setting, supply current, and signal voltage levels at the input and output pins of the device, so we can make further investigation.

        Thanks!

    Benjamin

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